Obira, on the Obirashibe River: Late Cenomanian - Early Turonian, Japan
List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
|
Osteichthyes
- Plesiosauria
- Polycotylidae
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Polycotylidae indet.
Williston 1908
|
1 individual | |||||||||
| UMUT MV 19965 (2 cervicals, 1 dorsal, 2 sacrals, 4 caudals, 3 indet. vertebrae partial pectoral girdle, ribs, right forelimb, fragmentary pectoral girdle, stomach contents) | ||||||||||
| see common names | ||||||||||
Geography
| Country: | Japan | State/province: | Hokkaido | County: | Rumoi District |
| Coordinates: | 44.1° North, 142.0° East (view map) | ||||
| Paleocoordinates: | 50.9° North, 144.4° East (Wright 2013) | ||||
| Basis of coordinate: | stated in text | ||||
| Geographic resolution: | small collection |
Time
| Period: | Cretaceous | Epoch: | Late Cretaceous |
| Stage: | Cenomanian - Turonian | 10 m.y. bin: | Cretaceous 5 - Cretaceous 6 |
| Key time interval: | Late Cenomanian - Early Turonian | Ammonoid zone: | Biostrina nipponica |
| Age range of interval: | 100.5 - 89.8 m.y. ago |
Stratigraphy
| Geological group: | Middle Yezo |
Lithology and environment
| Primary lithology: | massive lithified siltstone |
| Includes fossils? | Y |
| Lithology description: "This locality is relatively poor in megafossils compared with other parts of the Middle Yezo Group. The outcrops are mainly composed of monotonous siltstone, suggesting a constant supply of fine sediments in a low energy, offshore environment. The strata at the locality dip about 50 degrees west, and are almost perpendicular to the outcrop surface, suggesting that missing parts of the fossil had been eroded away before excavation. | |
| Environment: | offshore |
Taphonomy
| Modes of preservation: | body |
| Size of fossils: | macrofossils |
| Spatial orientation: | random |
| Preservation of anatomical detail: | medium |
| Abundance in sediment: | rare |
| Fragmentation: | frequent |
| Spatial resolution: | parautochthonous |
Collection methods and comments
| Collection excludes: | some macrofossils |
| Collection methods: | field collection |
| Collection size: | 1 individuals |
| Reason for describing collection: | general faunal/floral analysis |
Metadata
| Database number: | 102078 | ||
| Authorizer: | M. Carrano | Enterer: | H. Street |
| Modifier: | H. Street | Research group: | vertebrate |
| Created: | 2011-01-07 09:14:58 | Last modified: | 2025-02-22 15:12:02 |
| Access level: | the public | Released: | 2011-01-07 09:14:58 |
| Creative Commons license: | CC0 |
Reference information
Primary reference:
| 34686. | T. Sato and G. W. Storrs. 2000. An early polycotylid plesiosaur (Reptilia: Sauropterygia) from the Cretaceous of Hokkaido, Japan. Journal of Paleontology 74(5):907-914 [M. Carrano/H. Street] |